Originally the AR-15 / M16 had a Chrome plated Bolt Carrier Group. Later, when "officially" adopted by the Military in 1967 this feature was dropped.
Chrome is significantly easier to clean vs. Phosphate and may have some lubricity advantages when hot.
This Chrome BCG is correct for early 1960's model M16 variants (pre-1967) and includes forward assist serrations.
Includes authentic early style "machined" Retaining Pin.
The "slick side" version without serrations is (Here)
Bolt made from 9310 Steel
Carrier made from 8620 Steel
Compatible with 223, 5.56, 300 blackout